Various processes have been used in the past in forming socket wrenches. A successful technique is disclosed in U.S. Pat. No. 4,291,568 assigned to the assignee of this invention.
The socket wrench itself is a standard device, well known in the art, having a conventional square drive socket at one end, releasably attachable to a drive tang of a handle unit, and a fastener socket is coaxially formed at an opposite end of the wrench. The fastener socket is normally of hexagonal cross section. A through-hole extends between the coaxially aligned sockets and serves to provide clearance, e.g., for a shank of a bolt on which a hex nut is threadably engaged with the nut received within the hex fastener socket. For a quality product, such socket wrenches are normally formed of alloy steel.
Standard screw machines have been commonly utilized in the manufacture of such wrenches, as well as both hot and cold forging processes. The known methods of making such devices such as in U.S. Pat. No. 4,291,568 and other patent teachings exhibited by U.S. Pat. Nos. 4,166,373 and 4,061,013 each form the tool part from a solid cylindrical workpiece blank or slug. In this respect, it is common practice to normally begin a process with a solid workblank having a body size which generally corresponds to the outside diameter of the shank of the tool part which is of reduced size relative to a recessed end of the tool. U.S. Pat. No. 4,352,283 shows a method of cold forming spark plug bodies from a solid cylindrical blank. The state of the art also includes a variety of methods of working hollow pipe and tubing such as shown in U.S. Pats. Nos. 3,977,227, 3,735,463, 3,292,414, 1,982,874, 1,964,258, 934,174 and 381,355.
While the state of the art provides teachings of both hot and cold working of tubing, nonetheless, the known processes for making socket wrenches (and similar devices incorporating elongated hollow parts such as nutdrivers) have all utilized a solid metal billet from which the desired hollow elongated part is ultimately formed, presumably because of heretofore unsolved difficulties in forming such tool parts from original workpieces other than solid metal billets.